Field of the Invention
The disclosure provides catalyst materials useful for hydrogenating olefins and shifting carbon monoxide and methods for using such catalyst materials.
Description of Related Art
Many industrial processes, such as Fischer-Tropsch process, produce an off-gas (or tail gas) that contains hydrogen (H2), carbon monoxide (CO) and hydrocarbons (such as olefins), among other components. While some of the off-gas can be recirculated to the reactor, recirculation of all of the off-gas to the Fischer-Tropsch reactor causes CO2, CH4, and inerts to build up thus reducing the amount of hydrocarbons produced by the Fischer-Tropsch reactor. It can be desirable to use the off-gas stream to form commercially useful products, such as hydrogen. But the presence of olefins and CO in the off-gas stream can hinder its use in further reactions. As a result, olefins and CO are often removed from the off-gas stream. For example, olefins can be hydrogenated to paraffin and CO can be shifted to H2 and CO2.
Typically, olefins in the off-gas are hydrogenated over a Cu or Ni catalyst. The hydrogenation is typically followed by a shift reaction to convert CO and water to CO2 and H2 over a Cu- or Fe-based catalyst. These two steps typically require different catalysts. Or in cases where the same catalyst is used for both steps, the operating reaction conditions for the two reactions significantly different, such that they need to be performed in separate processes.